Problem: $ { \left[\begin{array}{rrr}{1} & {-2} & {4} \\ {1} & {-2} & {0}\end{array}\right]-\left[\begin{array}{rrr}{-2} & {4} & {-1} \\ {4} & {4} & {2}\end{array}\right] = {?} } $
Answer: To find the difference of two matrices, subtract the corresponding items between each matrix. ${\left[\begin{array}{rrr}{1}-{-2} & {-2}-{4} & {4}-{-1} \\ {1}-{4} & {-2}-{4} & {0}-{2}\end{array}\right]}$ Now, simplify: ${\left[\begin{array}{rrr}{3} & {-6} & {5} \\ {-3} & {-6} & {-2}\end{array}\right]}$